Feeding apparatus for yarn or the like



May 24, 1949. R. VIN

FEEDING APPARATUS FOR YARN OR THE LIKE 3 Sheets-Sheet 1 Filed Feb. 8. 1940 aria-M444 May 24, 1949. R, v 2,471,362

FEEDING APPARATUS 013 YARN OR THE LIKE Filed Feb. 8. 1940 3 Sheets$heet 2 Fig. 6 'avwcniob Eerie l/[n Fig. 7 Makolm' Fraser- May 24, 1%49. V|N 2,471,362

FEEDING APPARATUS FOR YARN OR THE LIKE Filed Feb. 8, 1940 3 Sheets-Sheet 3 Fig. 10

Malcolm )4! Fraser Patented May 24, 1949 THE LI Ren Vin, Paris, France, assignor to Socit Etablissements Poron, Troyes (Aube), France Application February 8, 1940, Serial No. 317,923 In France April 7, 1939 Claims. 1

The present invention has for its object, a process for feeding yarn or the like to a loom, at a constant, delivery and as a new manufactured product, a feeding apparatus for yarn or the like, adapted to supply ,the yarn to a knitting machine in such conditions that the resulting product will have the desired regularity.

For this purpose, the apparatus can deliver the yarn at each instant at the desired tension or speed, and particularly at constant tension or speed.

The apparatus differs from the ones which are already known, by the simplicity and eflicacity of the means employed, and for elastic yarns, in particular, it affords results which have not hitherto been obtained.

The said feeding device is chiefly characterized by the use of at least one rotatable device which is driven by any suitable means, upon which the yarn is caused to make several coils, and which cooperates with at least one stationary device for supporting the spiral coils of the yarn, and this permits, by rotating the said device at the desired speed, of modifying the tension of the yarn between the input end and the exit, and chiefly, when using a yarn having a variable tension at the input, of obtaining, at the exit, a tension which is practically zero, or again, when using a constant tension which is practically zero, at the input end, of obtaining at the exit a speed or delivery of the yarn which will be exactly constant.

Further characteristics of the invention will be set forth in the following description with reference to the accompanying diagrammatic drawings.

Fig. 1 is an explanatory diagram.

Fig. 2 is a diagrammatic perspective view of a device for the delivery of a yarn whose tension is equal to zero.

Fig. 3 is a like view of a modification.

Fig. 4 is a diagrammatic view of another device for obtaining a yarn having a constant delivery.

Fig. 5 is a front view of a construction according to the diagram shown in Fig. 4.

Referring to Fig. 1, according to the invention, the yarn is drawn between the feeding reel and g the knitting machine, upon a rotatable device I,

on which it is caused to make several coils. The tangential speed of the rotatable device is greater than the speed of the yarn, at each point.

There exists between the tension T of the yarn when it enters the reel and the tension t at the exit, the following well-known relation (belt formula):

in which e is the base of the neperian logarithms, j is the coefficient of friction between the yarn and the rotatable device, and a is the arc of windin It is thus observed that if, when a is constant, I

were constant, the tension at the exit would be a constant fraction of the intake tension, and the device would act as a tension reducer.

But I is variable, for different reasons, and thus the device in its present form will act properly as a reducer, but not as a regulator. Moreover, experiments show that the tension t at the exit is more irregular in percentage than the intake tension.

However, the present invention permits of obtaining, in all cases, an exactly constant tension, and this outgoing tension is in fact practically equal to zero, provided on has a sufficient value and the rate of rotation is satisfactory. Supporting means are provided in order to prevent the last turn or turns of the yarn (which are slack on account of the low tension) from becoming tangled, and interfering with the regular feeding of the yarn. Thus the apparatus according to the invention will act not only as a reducer, but also as a regulator of tension. 7

The supporting means which are shown diagrammatically at 2 in Fig. 1, preferably consist, as represented in Fig. 2, of stationary discs 2 which are mounted on a support 3 and are provided with apertures 4 for the coils of yarn, which are thus separated by the said discs.

The relation between the intake and exit tensions thus becomes:

in which I is the coefiicient of friction between the yarn and the supporting discs, and a is the arc of contact of the yarn with said discs.

In order that the apparatus works as a feeding device, it is necessary (and sufficient) that fa f'a', which is always easy to realize, and that the tangential smed of the rotatable device shall be greater than that of the yarn, at each point, taking due account of its elongation. 7

It will be readily understood that according to the above equation, a. varies at each instant to give an output tension which is practically equal to zero, by dividing the coils passing over the device into two groups, the intake group, in which the coils fit upon the 'device, and the ontake group, in which the coils are slack and are held by the supporting'discs 2.

I Thus the ofitake tension will always remain the same, whatever be the rate of delivery, provided it is less than the speed of the feeder the yarn being stretched, this being quite important for the regularity of the work performed. Moreover, another most important advantage consists in the fact that in the case of intermittent delivery (for instance for reciprocating knitting machines), if the knitting machine ceases to take in yarn at a given instant, all the coils will become slack, but by the use of the supporting members, the yarn remains stationary and will not become tangled, when the feeder keeps on with rotation.

Fig. 3 represents a modification which comprises two drums and 6, and the supporting discs I surround both drums at the same time. In this apparatus, f'a. is much less than fa, a being greater. for a given number of coils, while a depends only upon the passage of the yarn at 8 and thus has a small value. The passage of the yarn in the open slots 8 is also made easier, as the part which supports the discs (not shown) is mounted between the two cylinders inside of the coils.

The yarn which is fed under a tension and an elongation which are equal to zero, can be used directly in the knitting machine without any tension or at a constant tension which may be given to it by any suitable device such as a pair of pressing washers, known per se; or at a determined speed by means of a set of two pressing rollers, cylindrical or tapered, or the like, but preferably by means of a rotating device analogous to the preceding.

In fact, it has been shown by theory and experiments that it is possible to employ the apparatus as a delivery limiter which operates with a precision at least as great as pressure rollers, while maintaining the characteristic advantages of not damaging the fragile yarn and of automatically stopping or limiting its delivery according to the requirements of the knitting apparatus.

Let t be the tension at the input of the feeder, and 1) its tangential speed. If the knitting apparatus tends to take up the yarn, which would be supplied to it directly at this tension P, at a speed greater than 1;, the feeder will limit the delivery of the yarn, used at this tension t to the speed a, which speed may be constant or controlled at will. It' is thus observed that the precision of the delivery will depend entirely upon the constancy of t or more exactly, upon the constancy of the elongation of the yarn, which depends upon this latter.

It is advantageous to use for t a tension which is practically equal to zero, such as is furnished by the first apparatus. This corresponds to an elongation which is also equal to zero, and hence to a very exact delivery.

It is possible to combine in a single apparatus, as shown in Fig. 4, a feeding drum 9 whose exit tension is equal to zero, with a drum l0 whose input tension is equal to zero and whose delivery is constant, and this will provide a feeder whose delivery is strictly constant in spite of an input tension of any value, which may be variable. The ratio between the diameters of the two drums corresponds to the maximum elongation of the yarn, i. e. to the breaking of said yarn, or to the release of a known uncoupling device not shown. The supporting discs have been shown diagrammatically in the figure at 2a, but in fact, they are analogous to those of Fig. 2.

Fig. 5 shows an embodiment which again comprises, without need of a further description, the parts shown in the preceding figures. The yarn arrives at II; it is wound upon the drum I2, and its turns pass between the plates 22 through the apertures [4. At the base, the yarn passes over a yarn-guide 15, without tension. It proceeds over a yarn-guide Hi from which it passes to a guiding and supporting device I'l having orifices 18 for the passage of the coils. These latter cover the drum I9 and leave at 20, at the desired tension and speed.

An adjustable transmission 2| provides for the driving of the two-drum apparatus at the desired speed, as above set forth.

Fig. 6 shows a detail of a device for guiding the yarn on the supporting discs 22 Without risk of damaging the yarn by jamming in the space between the discs and the drum. Instead of adjusting the guide discs with respect to the drum, without play, which would be somewhat difllcult, washers 23 of triangular section. are placed loosely upon the discs, and can be readily adjusted, as they are mounted freely and are not secured. In this case, the discs 22 can be given a diameter which is clearly greater than that of the drum, and the discs can be mounted without taking account of any eccentricity, which is now of no importance.

Fig. '7 shows another modification, in which the upper drum 24 comprises discs 25 by which the spiral turns of yarn can be better separated and supported, without risk of damage, for instance when the yarn is not taken up'by the knitting machine, on reciprocating knitting machines, or in like circumstances.

Figs. 8 and 9 show another embodiment of the invention in which a supporting member 26 is mounted between two parallel drums 21 and 28. The member 26 surrounds the said drums upon a part of their periphery. The parts are to be assembled in such way that there will be no play between the said member and the drums at the points 29, i. e. at the ends of the member which are closed to th drums.

However, in the intermediate portions, a slight Play can be allowed between the said member and the drums, as shown by the dotted line 41.

The member 26 is provided with helicoidal ribs 30. Separating discs 3| are mounted on the ends of the ribs 30 so as to surround the remaining part of the periphery of the drum.

The device shown in this figure may be combined with a second feeding device similar to that disclosed in Fig. 5, The cylinders 32, 33 each carry sprockets 31', around which is a chain 39 engaging with another sprocket 38. This sprocket is carried on a drum or rotating member 40 mounted to turn in member 34 between drums 32, 33. Also upstanding from member 34 is a guide 4| having guide openings 42 similar to the openings l8 of Fig. 5. The yarn is led from the lower end through eyelets 43 and 44 and holes 42 to make several turns around drum 4!] and is led ofl through eyelet 45.

The operation of this embodiment is similar to that of the modification shown in Fig. 3, but in this case, slack coils of the yarn are supported by the ribs in cooperation with the discs 3|.

In fact, it has been shown by experience that such guiding will prevent the yarn from entangling or from jamming against the guiding parts. It has been found that it is sufiicient, for this purpose, to prevent any play at the points 2-9, but that the absence ofplay will not be necessary upon the remainder of the periphery of the drums surrounded by the member 26.-

Figs. 10 and 11 relate to another modification. In this embodiment there is provided, between the two drums 32 and 33, as in the preceding embodiment, an inner member 34, the width of which is greater than the diameter of said drums, and

helicoidal grooves 35 are cut in the member 34, whichgrooves are intended to support the slack coils of the yarn. Owing to the friction of the yarn in these deep and narrow grooves, the discs 3| shown in Figs. 8 and 9 can be eliminated. The yarn is held in the grooves 35 by removable rods 36 which are parallel to the drums 32 and 33.

Obviously, the forms of construction herein described and represented are given solely by way of example, and it is possible, without departing from the spirit of the invention, to suitably modify the number, form, disposition and mounting of the several parts.

What I claim is:

1. In a feeding apparatus for yarn or the like, the combination of a rotatable cylinder, mounted on a driving shaft, on which the yarn is caused to make a number of coils; a frame supporting said shaft; supporting plates rigid with said frame and surrounding said cylinder; means for guiding each coil of yarn from one side of a supporting plate to the other side; a second cylinder mounted on the same driving shaft, said second cylinder having a smaller diameter than the first cylinder; means adapted to guide the yarn from the output of said first cylinder to the input of said second cylinder; and an apertured device adapted to guide and support the coils of yarn round said second cylinder.

2. In a feeding apparatus according to claim 1 the provision of washers which are loosely mounted on each plate to cooperate with the first cylinder in order to avoid clearance between said plates and said cylinder.

3. In a feeding apparatus for yarn or the like, the combination of a rotatable means having at least one surface around which the yarn makes a number of coils, means to drive said first means, stationary supporting means closelyadlacent at least part of said surface for the last coils of the yarn, and-a rotatable device driven at a lower tangential speed than the first mentioned means.

andon which the yarn fed by the rotatable means makes a small number of coils.

4. In a device as claimed in claim 3, said stationary supporting means surrounding at least partially said first means.

5. In a feeding apparatus for yarn or the like,

the combination of at least one rotatable element having at least one surface around which the yarn makes a number of coils, means to drive said element, stationary supporting means for at least the last coils of the yarn, said stationary supporting means surrounding at least'partially said rotating element, and a 'rotatable'device driven at a lower tangential speed than the first rotating element from the same shaft and on which the yarn fed by the rotating element is caused to make a small number of coils.

6. In a feeding apparatus for yarn or the like, the combination of at least one rotatable cylinder having at least one surface around which the yarn makes a number of coils, means to drive said rotatable cylinder, stationary supporting means closely adjacent .at least part of said surface ior the last coils of the yarn, said supporting means surrounding at least partially said rotatable cylinder, and a second rotatable device driven at a lower tangential speed than the said cylinder, and on which the yarn fed by the said cylinder makes a small number of coils.

'1. In a feeding apparatus for yamor the like, the combination of at least one rotatable cylinder round which the yarn is caused to make a number of coils, means adapted to drive said rotatable cylinder, stationary supporting means for at least the last coils of the yarn, said means surrounding at least partially said rotatable cylinder, and a second rotatable device driven at a lower tangential speed than the said cylinder and on which the yarn fed by the said cylinder is caused to make a small number of coils.

VIN.

REFERENCES CITED The following references are of record inthe file of this patent:

UNITED STATES PATENTS 

